Transseptal access device and method of use

ABSTRACT

Systems, devices, and methods are provided for transseptal access of septa within a patient. The device can be advanced to a septum, e.g., towards a fossa ovalis. Instead of applying positive pressure to “tent” the septum, a negative pressure is applied to a lumen within a sheath, e.g., within an elongated member slidable within the sheath, via a negative pressure source such as a syringe on the proximal end of the sheath. This results in the septum pulling inward. The sheath employs a stationary needle-like central core component contained within the lumen of the sheath that punctures the septum when the same is pulled passed it by the negative pressure. The stationary needle-like central core component may be hollow and may form a portion of the elongated member or may be coupled to a distal end thereof

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 16/282,366, filedFeb. 22, 2019, which is a continuation of U.S. Ser. No. 14/667,155,filed Mar. 24, 2015, entitled, “TRANSSEPTAL ACCESS DEVICE AND METHOD OFUSE” which is a Continuation in Part of U.S. Ser. No. 14/567,427, filedDec. 11, 2014, entitled, “TRANSSEPTAL ACCESS DEVICE AND METHOD OF USE”and also claims benefit of priority of U.S. Provisional PatentApplications Ser. No. 61/969,453, filed Mar. 24, 2014, entitled “SYSTEMSAND METHODS FOR PROVIDING ATRAUMATIC ACCESS THROUGH TISSUES”; U.S. Ser.No. 14/567,427 is a Divisional of Ser. No. 13/093,546, filed Apr. 25,2011, now U.S. Pat. No. 8,940,008 issued Jan. 27, 2015, entitled“TRANSSEPTAL ACCESS DEVICE AND METHOD OF USE”; which claims benefit ofpriority to U.S. Provisional Patent Application No. 61/327,542, filedApr. 23, 2010, entitled “TRANSSEPTAL ACCESS DEVICE AND METHOD OF USE”,U.S. Provisional Patent Application No. 61/359,674, filed Jun. 29, 2010,entitled “TRANSSEPTAL ACCESS DEVICE AND METHOD OF USE, and U.S. SerialProvisional Patent Application No. 61/443,483, filed Feb. 16, 2011,entitled “TRANSSEPTAL ACCESS DEVICE AND METHOD OF USE”; all of the aboveare herein incorporated by reference in their entirety.

BACKGROUND

In many procedures, it is necessary to obtain access through bodilytissues. For example, in many cardiac procedures it is necessary toobtain access through the cardiac septum. Prior efforts to obtain accessinclude piercing a small hole in the septal wall, typically at alocation called the fossa ovalis (“FO”). Such access is term transseptal(“TS”) access.

TS access is often performed by delivering a sheath/dilator through thevenous bed into the right atria and to the septal wall. With the tip ofthe dilator dragged along the septal wall, the same is dragged to thelocation of the FO. The sheath is then slightly advanced forward,applying pressure to the FO, creating what is called “tenting” of theFO. A long TS needle, e.g., a “Brockenbrough or “BB” needle, is thenadvanced through the lumen of the dilator that is inserted through thesheath. The needle is advanced against the FO while it is tented. Theneedle then punctures through the FO and into the left atrium.

The TS needle may be hollow or may incorporate a guide wire lumen toenable fluid delivery, and /or a guide wire or other minimally invasivetools to be threaded through and into the left atrium of the heart. Oncethe guide wire is passed through the TS needle into the left atrium, theneedle, dilator, and sheath maybe retracted while the guide wire remainsin the left atrium for subsequent procedures.

In about 20% of TS cases, there is difficulty obtaining TS accessbecause of highly fibrosed tissue from previous TS procedures.Additionally, the TS sheath and the BB needle, as the same are beingpushed forward by a physician, often slide up or down instead of theneedle moving forward to penetrate the tissue, increasing the tension onthe FO, causing the same to tent further adding additional stress to thetarget tissue, again while the needle attempts to penetrates the tissue.In other cases, if the septum is heavily fibrotic, significant pressureis required to advance the TS needle into the left atrium. Both casesoccasionally cause puncture of the opposite wall of the left atrium bythe sudden exertion of the needle through the septum and subsequentperforation, causing a severe adverse event and potential for death. Toaddress this several currently marketed TS devices require RadioFrequency (RF) delivered to the needle to penetrate said target tissuein heavily fibrosed septums.

SUMMARY

The current invention provides a system and method for achieving TSaccess while minimizing complications associated with obtaining TSaccess. In one implementation, the system includes a device that atleast in part replaces the dilator and/or the needle. The device has aflared distal end, e.g., with a funnel-shaped polymer element that isradiopaque attached to the distal portion of a dilator element orneedle, and within the flared distal end, a vacuum, suction, or othernegative pressure may be applied. Also within the flared distal end is acenter core section equipped with a pointed feature like a needle. Withthe use of a syringe or other source of negative pressure connected tothe proximal end of the device, negative pressure is applied and thefunnel tip prolapses, pulling the FO towards the stationary needlefeature, puncturing the FO and obtaining access to the LA. A guidewiremay then be advanced through a hollow portion of the puncturing featureof the TS access device for subsequent procedures.

In one aspect, the invention is directed to a method of gaining accessthrough a septum, including: delivering a device to a selected locationat a septum, the device including a funnel with a proximal end and adistal end and an interior therebetween, the distal end having a greaterradius than the proximal end; placing the distal end of the funnelagainst the selected location; drawing a negative pressure in theinterior, such that a portion of the septum and selected location arepulled within the interior of the device; and continuing to draw anegative pressure in the interior until an indication is received thatthe septum has been pulled past a stationary needle disposed within theinterior.

Implementations of the invention may include one or more of thefollowing. Upon receipt of the indication, the negative pressure may beincreased to zero or a lumen in which the negative pressure was drawnmay be valved off. The drawing a negative pressure may include couplinga syringe to a lumen, the lumen in pressure communication with theinterior, and pulling back on a plunger of the syringe. The selectedlocation may be a fossa ovalis. The negative pressure drawn may bebetween about that drawn by a 5 cc syringe and that drawn by a 100 csyringe, and even more between about that drawn by a 10 cc syringe andthat drawn by a 20 cc syringe. The indication may be a presence of bloodin a lumen in which the negative pressure was drawn or a reduction inthe amount of negative pressure drawn. The method may further includeinserting a guide wire through the device such that a distal tip of theguide wire is disposed in a desired location of the heart.

In another aspect, the invention is directed to a non-transitorycomputer readable medium, comprising instructions for causing acomputing device to perform the above method.

In yet another aspect, the invention is directed to a device fortransseptal access, including: an elongated member having a proximal endand a distal end, and a piercing element disposed at the distal end; anda funnel coupled to the elongated member at the distal end, the funnelhaving a proximal end with a first radius and a distal end with a secondradius, the second radius greater than the first radius, the funnelhaving a retracted configuration and an expanded configuration, theexpanded configuration defining an interior; and the device is such thatthe elongated member, the needle, and the funnel are configured to bedelivered to a septal location through a transseptal sheath, and suchthat upon removal of the funnel from the sheath, the funnel assumes theexpanded configuration, and such that a pressure lumen is defined in theelongated member extending from the proximal end and into the interiorof the funnel.

Implementations of the invention may include one or more of thefollowing. The first radius may be between about 3 French to 10 French,and the second radius may be between about 2.5 mm to 15 mm. Even more,first radius may be between about 5 French to 8 French, and the secondradius may be between about 5 mm to 10 mm. The device may furtherinclude a fitting attached to the pressure lumen at the proximal end ofthe elongated member, the fitting configured to attach a negativepressure source thereto. The fitting may be configured to attach asyringe thereto. The funnel may further comprise a lip formed at thedistal end. The negative pressure source may be configured to draw anegative pressure of between about that drawn by a 5 cc syringe and thatdrawn by a 100 c syringe, and even more between about that drawn by a 10cc syringe and that drawn by a 20 cc syringe. The funnel may furtherinclude a rib, a spine member, or a pleat. The spine member may beattached to the funnel or not. The funnel may have a straight shape or aconvoluted shape. The elongated member may have further defined aguidewire lumen therein, the guidewire lumen extending from the proximalend and into the interior of the funnel. In the retracted configuration,the funnel may substantially surround the stationary needle. In theexpanded configuration, the funnel distal end may extend further in adistal direction than does the piercing element. The piercing elementmay be a stationary needle coupled to the elongated member at the distalend. The piercing element may be a dilator with a sharp tip. The funnelmay be formed of a shape memory material, such as a polymer, and the ribor spine member may be comprised of a shape memory metal. The shapememory metal may be nitinol.

Advantages of the invention may include one or more of the following.The chance of puncture of cardiac walls is reduced by pulling in the FOwith the negative pressure towards a stationary needle. This system maybe combined with other devices, e.g., with a needle tip that curls afterpuncture, for an especially safe procedure. Another safety feature isthat during delivery of the TS Access device, the funnel-shaped polymerelement may be caused to collapse around the needle or penetrating,piercing, or puncturing element during delivery thru the sheath,protecting the needle from skiving the inner surface of the sheath whilebeing delivered to the target location.

Other advantages will be apparent from the description that follows,including the figures and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic view of a transseptal access systemaccording to an implementation of the present invention.

FIGS. 2(A)-(G) illustrates side schematic views of a transseptal accesssystem according to an implementation of the present invention, showingsteps of the use of the system in penetrating a septum.

FIG. 3 illustrates a side schematic view of a transseptal access systemaccording to an implementation of the present invention, particularlyshowing exemplary locations through which negative pressure may beapplied, as well as guidewire lumen locations.

FIG. 4 illustrates an end-on view of a of a transseptal access systemaccording to an implementation of the present invention, showing spinemembers, pleats, and ribs.

FIG. 5 illustrates a side schematic view of a transseptal access systemaccording to an implementation of the present invention, showing a lipproviding an enhanced coupling to the septum of some patients.

FIG. 6(A)-(B) illustrate side views of a ribbed funnel, illustratingstraight sides (A) and convoluted sides (B). Other types of funnels mayalso be employed.

FIG. 7 is a flowchart illustrating a method according to animplementation of the present invention.

FIG. 8 illustrates a side schematic view of another transseptal accesssystem according to an implementation of the present invention.

FIG. 9 illustrates a view of a funnel including a partial funnel withmultiple segments.

FIG. 10 illustrates a side sectional view of a device according topresent principles

FIGS. 11A-11C illustrate steps in deployment of a device according topresent principles.

FIG. 12 illustrates a sectional view of a device according to presentprinciples.

FIGS. 13A-13F illustrate steps in deployment of a device according topresent principles.

FIGS. 14A-14D illustrates a variation of a device according to presentprinciples.

FIG. 15 illustrates a sectional view of a device according to presentprinciples.

FIGS. 16A-16B illustrates a variation of a device according to presentprinciples.

FIGS. 17-30B illustrate variations of types of funnels.

FIGS. 31-39 illustrate variations of types of funnels including a“bullet” element configured to assist funnel deployment.

FIGS. 40A-40J illustrate steps in funnel deployment.

Like reference numerals refer to like elements. Elements are not toscale unless otherwise noted.

DETAILED DESCRIPTION

U.S. patent application Ser. No. 13/093,546, now U.S. Pat. No.8,940,008, owned by the assignee of the present application and hereinincorporated by reference in its entirety, describes various systems andmethods by which atraumatic TS access may be obtained. This applicationdescribes further such implementations of systems and methods.

Implementations of the device and method include a device that can beadvanced to a septum, e.g., towards a FO. In this exemplaryimplementation, instead of applying positive pressure to “tent” the FOtoward the LA, a negative pressure is applied to a lumen within thesheath, e.g., within an elongated member slidable within the sheath, viaa negative pressure source such as a syringe on the proximal end of thesheath. This results in the FO pulling inward. The sheath employs astationary needle-like central core component contained within the lumenof the sheath that punctures the FO when the same is pulled passed it bythe negative pressure. The stationary needle-like central core componentmay be hollow and may form a portion of the elongated member or may becoupled to a distal end thereof.

After the puncture occurs, a guidewire may be threaded through thepuncture and into the LA. The negative pressure creates a stable basefor the TS puncture to occur. Moreover, by reversing the prior artprocess (by pulling the FO past the needle contained within the sheath),the chance of perforation is significantly reduced if not eliminatedduring TS procedures. In an alternative embodiment, the design may alsoincorporate ultrasound or other technology within the funnel shapedstructure to enable better visualization of the FO prior to the punctureprocess to further eliminate perforation of adjacent structures. Apressure sensor located at the tip of the needle-like feature may alsoprovide real-time feedback to the user to verify TS access has beenachieved. The same may also provide information regarding the level oftension on the FO. Furthermore, a ring of electrodes affixed to the rimof the funnel feature configured in a uni-polar and or bi-polarconfiguration may also be adapted to further assist alignment and tissuecontact of the device prior to crossing the septum. The device may be ofa fixed curve (in a number of sizes and radii of curvature) or steerablesheath design and may include variations in length and diameter forvarious applications.

FIG. 1 illustrates one implementation of the current device. A device 10has a proximal end 16 and a distal end 14. The device 10 includes afunnel 24 extending from an elongated member 12 that slides within astandard TS sheath 36. The TS sheath 36 may be, e.g., an 8 Frenchsheath. In FIG. 1, the funnel is shown in an expanded configuration.However, when within the sheath 36, the funnel is in a retractedconfiguration. In use, the funnel 24 is configured to engage a FO usinga source such as a syringe at the proximal end 16 of the device. Anegative pressure or vacuum is drawn to pull in the FO to the piercingelement or needle 26, enabling access to the LA. That is, the FO ispulled toward the piercing element or needle and eventually the FO ispulled past the piercing element or needle, causing the piercing elementor needle to penetrate the FO. It is noted that the piercing element orneedle may be stationary with respect to the sheath, the guide wire,and/or the remainder of the heart. It is the FO that may be caused tomove in a direction so as to be penetrated by the piercing element orneedle; the FO need not be actively penetrated by a moving needle orpiercing element.

FIGS. 2 (A)-(F) illustrate the above movement of the funnel 24 and FO ofthe septum past the stationary needle or piercing element 26 andelongated member 12, which may be generally a catheter main body polymertubing. In (A), the device is situated away from the septum, but thefunnel has been extended past the sheath and thus is in a flared orexpanded configuration. In (B), the device abuts the septum, but nonegative pressure has yet been drawn. In (C), a negative pressure orvacuum begins to pull on the septum, e.g., the FO, such as by a syringeor pump which is in pressure communication with an interior 31 of thefunnel. In (D), the negative pressure increases, and the funnel 24begins to flare out even more. It is noted in this regard that in FIGS.2 (A)-(F), the movement of the septum is not shown; it is however shownin FIG. 2 (G). In (E), the funnel 24 flares out even more as the septumis pulled towards the needle, and in this figure the needle or piercingelement 26 begins to pierce the septum. In (F), the FO has completelymoved past the needle 26 because of the applied negative pressure. Asnoted above, FIG. 2(G) illustrates schematically the movement of theseptum, e.g., the FO, towards the stationary needle 26, as a result ofthe drawn negative pressure.

FIG. 3 illustrates additional details of the distal tip of the elongatedmember 12, including the funnel 24. In particular, the distal tip 14 ofthe elongated member 12 is illustrated with the funnel 24 in theexpanded configuration. The funnel may be seen to be coupled to theelongated member 12 by virtue of a bond 38. Another bond 39 may beemployed to attach the needle or piercing element 26 to the distal tip14 of the elongated member 12.

Negative pressure may be drawn by one or more vacuum or pressure lumens27, while one or more guide wire lumens 29 may be employed to pass aguide wire, e.g., into the LA of the heart. Of course, it will beunderstood that in any given implementation only one guide wire lumenmay be required. One or more pressure lumens may be employed to draw thenegative pressure, pulling the septum past needle or piercing element26.

Referring back to FIG. 1, a hemostasis valve 32 may be employed to sealthe handle, so as to allow a vacuum and yet enable the user to advanceand retract the guide wire during use. A handle 22 is located on theproximal end of the TS access device. A side port tube 34 and syringehub may be connected to the handle, providing fluid exchange with theinner lumens of the TS access device. Such facilities allow the user toaspirate the lumen to create a vacuum against the septum of the heart,e.g., at the FO, or at other locations along the septum.

Referring to FIG. 4, an end-on view is illustrated of the funnel 24. Anumber of elements may be employed to enhance the structural integrityof the funnel 24, although not all elements need be employed in everysituation, and in many cases no such elements may be employed. First, toassist in the flaring of the funnel, spine members 42 may be employed.The spine members 42 may be attached to the funnel or not, but in anycase provide a degree of spring action to flare or fan out the funnelwhen the same is outside of the sheath. A number of pleats 44 may beemployed, the same allowing the funnel to flare out. A number ofcircumferential ribs 46 may also be employed to assist in the shaping ofthe flared funnel 24, and these ribs 46 are further discussed below. Thespine members and rib members may be made of nitinol wire. However, thepolymer of the funnel alone may be designed so as to have memory as welland/or an inherent geometric shape, which may incorporate the pleatsnoted above, to help the polymer funnel element to deploy into thefunnel shape.

In FIG. 4 it is noted that the funnel may be of a soft durometer polymerand can include an additive providing a radio-opaque feature forvisualization under fluoroscopy. The flared tip may be soft,thin-walled, and designed to prolapse during application of vacuum,allowing the FO to be forced into contact with the piercing element orneedle. In another implementation, the needle may be attached to amechanism that can be advanced following vacuum application to the FOallowing a controlled perforation of the septum.

As noted above, the piercing element or needle may be bonded to theinside surface of the TS access device. The piercing element or needlemay be of a hollow design. After the puncture of the septum occurs, aguidewire can then be advanced through the hollow piercing element orneedle through guidewire lumen 29, and advanced into the LA thru thepuncture provided.

FIG. 5 illustrates that the funnel 24 may have a lip 48 disposed at adistal end thereof, the lip circumferentially surrounding the funnel 24.The lip 48 provides an even greater attachment of the funnel 24 to theseptum. This figure also shows the proximal end 33 and a distal end 35of the funnel 24.

FIG. 6 (A)-(B) illustrate that the funnel 24, including ribs 46, mayhave a straight conical profile 52 or may have a convoluted profile 52′.In some implementations, the convoluted profile 52′ allows for easierfolding into the sheath 36 as well as enhanced attachment to the septum.

FIG. 7 illustrates a flowchart embodying a method of the invention. In afirst step, access is gained to the right atrium (step 54). In thisstep, a femoral or other vein is accessed, allowing movement of devicestowards the heart and into the right atrium through the inferior venacava. A next step is to deliver the TS access device to the right atriumusing a sheath (step 56). The needle and funnel are extended from thesheath, causing the funnel to expand by virtue of its own memoryelement, memory metal in spine or other members, or both. A next step isthat the needle and funnel are directed towards the septum, and commonlytowards the FO (step 62). A next step is the placement of the needle andfunnel assembly against the FO (step 64). A next step is to draw avacuum or negative pressure, pulling the FO towards the needle (step66). The vacuum or negative pressure may be drawn using any of themethods described above, including by use of a syringe or micro pump. Anext step is to stop the negative pressure drawing once an indicationhas been received that the FO has been penetrated by the needle (step68). The indication may be by the detection of the presence of blood inthe lumen that draws the negative pressure, a reduction in the measurednegative pressure, or the like. Where a reduction in the negativepressure is used, a measurement device may be employed to measure thepressure during the drawing step. A next step is to ensure that a guidewire is in place, e.g., by extending the same through the needle (step72). A next step is to retract the needle and funnel, as well as thesheath and any dilator that may have been used (step 74). The proceduresrequiring TS access may then be performed (step 76).

The device significantly improves the safety profile of such procedures,simplifies the same, and reduces the time needed to achieve LA access.

In another implementation, shown in FIG. 8, a portion of a needle 26′may be embedded into a semi-flexible tubular element similar to adilator. In this implementation, a portion of a long needle, which maybe similar to a BB needle, has a flexible polymer24′ affixed to itsdistal portion. The distal end portion polymer portion 24′ is affixed tothe outer curved portion of a needle by bonds 15 and, during use in thebody, the portion 24′ deploys into a funnel-like shape.

Certain manufacturing details are now described. The needle may alsohave a proximal end on which is disposed a luer fitting for a syringe.The tapered or funnel-shaped polymer portion affixed to the distal endmay incorporate pleats, such as on some balloons, to help impart a foldduring insertion and withdrawal of the device. Furthermore, duringinsertion and withdrawal of the device, the polymer distal portion mayextend past the needle tip and, with the pleats, fold around the distaltip of the needle, protecting the needle from skiving the inner surfaceof the sheath during movement through the sheath while being insertedinto the body.

The prolapsed orientation of the funnel 24 during partial retractioninto the sheath 36 enables the inner core to perform as a typicaldilator. The tapper portion of the dilator used in a similar way to thedilator of a traditional TS sheath sends tactile information to theproximal end of the dilator where the end-user, grasping the proximalend, can feel the dilator and sheet moving along the septum onto thelocation of the FO. Furthermore, with the funnel 24 partially extendingfrom the distal end of the sheath, this creates a tapered geometrysimilar to the traditional dilator, enabling the tapered portion togradually access the puncture site made by the needle 26. The funnelalso provides a positive stop for the needle, thereby acting as a safetyfeature, preventing the through—and—through perforation common totraditional TS access devices.

After insertion and attainment of the target location, the needle isdeployed thru the distal tip of the device. The polymer distal portionmay then deploy like an inside-out umbrella against the septal tissue.The needle may be located slightly back from the deployed plane of thepolymer funnel portion. Then, using a syringe, a vacuum, suction effect,or other negative pressure between the funnel polymer portion and tissueallows the soft flexible polymer portion to flatten out, pulling theseptal tissue inward toward the needle and piercing the septal wall foraccess to the LA.

Aspects of certain implementations follow.

In some implementations, the funnel is flexible and can flattensubstantially perpendicularly to the axis of the lumen of the cathetershaft. In some implementations, when the distal end is flattened againstthe septum, exposing the tip of the needle-like element, the sameextends at least 1mm past the planar surface of the flattened portion ofthe funnel-shaped distal end. The funnel may be mechanically capable offlattening by advancing the catheter forward or by creating a negativepressure with the use of a syringe. The needle element may employ atapper, the tapper being sharp enough to penetrate cardiac tissue. Thefunnel-shaped distal segment may have a range of angularity from 90 to180 degrees. In another implementation, the funnel distal portion couldbe attached to a needle, a dilator or a sheath. In some implementations,the distal portion of the device may employ a pressure transducer tomeasure cardiac pressure and pressure changes, to define when TS accessis achieved. In some implementations, a device is provided such that thedistal portion of the device employs an ultrasound element capable ofvisualizing TS access locations prior to puncture of the FO.

In some implementations, a device is provided where the needle-likeelement is attached to a tubular element that is advanced distally orproximally by the use of a knob located at the handle of the device. Insome implementations, a device is provided having a flexible distalportion to enable steering via a mechanical mechanism located at thehandle of the device. In some implementations, a device is providedhaving a proximal end that includes a handle element having a mechanicalslide connected to a tubular structure and a needle or piercing elementlocated at the distal tip, enabling movement in a distal and proximaldirection. A proximal end may have a handle that includes a haemostaticvalve (e.g., a Merit Medical Passage hemostasis valve (pin 500066)) forguidewire insertion and a luer port (e.g., a Qosina Male Touhy Borst(pin 60343)) to connect a syringe. The hemostasis valve enablesinsertion of a guidewire or other device and prevents blood from exitingthe handle. The sheath portion of the device may employ a fixed curve ormay be configured to enable deflection via a steering mechanism at oradjacent to the handle. In this way, the device may be more convenientlydirected to a particular location. Where the device employs a fixedcurve, a number of difference radii of curvature devices may be providedfor use.

In some implementations, a device is provided that, following access tothe LA, can be used to deliver contrast to the LA via a syringe througha luer fitting situated on the proximal end of the device, for thepurposes of performing venograms.

In some implementations, the cutting element may be slightly off axisand may extend past the surface defined by the lip. In someimplementations, a governor or other means may be implemented to inhibitmovement of the cutting element past a pre-specified point. In this way,a significant safety factor is added. The mechanism that pushes theneedle may be similar to those used to extend the point of a ball pointpen (and to retract the same as well).

The elongated member may be a modified dilator. The cone may befabricated from Sorta-Clear 40A silicone, and may be bonded to themodified dilator using a bond with RTV.

As noted above, variations may be seen especially in the features of thefunnel. For example, the funnel may be folded by collapsing in steps, ascaused by ribs, so as to allow for easier folding. The wall of thefunnel may have a relatively constant thickness, or may have a varyingthickness. It has been found that particularly good results are obtainedwhere the wall thickness incorporates a taper, e.g., becomes thinner inthe distal direction. In the manufacturing implementations of theinvention, a catheter section may be bonded to a cylindrical sectionmounted to the funnel.

Other variations of the invention will also be seen. For example, thepiercing or puncturing or penetrating element may incorporate variousshapes of needles, or the same may incorporate RF, resistive, orinductive heating, so as to “burn” a hole in the septum in a convenientfashion. Where a negative pressure is pulled through a hole in theneedle, the same may be pulled from the side of the needle or from thetip. Where the negative pressure is pulled from the tip, depending onthe diameter of the needle, some septal tissue may be pulled into theneedle. In most cases, however, a hole will still be caused in theseptum using this technique.

Yet other variations of these designs will also be seen. For example, insome cases it has been found both sufficient and efficient to replace afull funnel with one in which a partial funnel 78 (see FIG. 9) extendspartway distally while multiple segments extend distally from thepartial funnel to the distal end. In a specific implementation, eightsuch “fingers” extend from the partial funnel to the distal end, similarto the tentacles of an octopus. This embodiment has the advantage thatthe same is easy to fold for insertion (as less folding is required),while still being capable of forming a sufficient negative pressure topull the septum towards the needle and vice-versa. In this connection itis noted that one negative pressure that has been found sufficient isthat drawn by retraction of a syringe, e.g., in the range of 10 to 20cc. In this or in other implementations, the funnel may be deployed byhaving the same heat shape set, e.g., with a memory alloy having an AFtemperature range of 10 to 25° C. And as mentioned before, the guidewirecan allow for multiple deployments of treatment devices following theseptal puncture. Treatment devices may even be loaded in a cartridgesystem for multiple easy deployments, where the cartridge system may bemated to the guidewire. Other inventions will also be apparent to one ofordinary skill in the art, given this teaching. Certain other variationsare described below, and others will be apparent to one of ordinaryskill in the art.

In certain implementations, transseptal access devices and proceduresaccording to present principles are designed to reduce the stressinduced into the tissue (FO) to minimize and reduce fibrosis fromscarring said target tissue location over currently available andmarketed TS access devices.

They generally overcome this without the need for RF being delivered tothe needle. The devices enable a novel use of vacuum or negative or lowpressure to hold and or encourage the tissue towards the needle whilethe physician through the use of a knob located on the proximal end,i.e. handle, advances a needle forward (if necessary) to puncture thetissue. This device overcomes the limitations of the conventional and RFTS access devices by using the vacuum to enable the device to maintainposition, and pull the tissue into the cone thinning the tissue andenabling the needle to simply and safely penetrate the tissue with aminimal amount of force required by the end user. Additionally, thissimple change in the methods eliminates the sudden release of tension bysaid tissue that causes perforations known to conventional TS accessdevices. Moreover, ultrasound or RF energy may also be added to activatethe needle for very difficult and thickened septal tissue. The devicedescribed may have alternative uses in addition to TS access such asused within a vessel that is full or partially occluded. The devicemaybe deployed into said vessel encounter said blockage, deploy thedistal segment the cone maybe used to center said device within saidvessel and the needle advanced thru the blockage, lastly a guidewire maythan be advanced thru lumen of said needle to pass thru and dilate alesion within said vessel lumen. Furthermore, the needle of the proposeddevice may also enable the conductance and delivery of an energy sourcesuch as ultrasound or RF energy to reduce the amount of force requiredto penetrate and open a blocked or partially blocked vessel.

In one implementation, depicted in various illustrations in the figures,such as in FIG. 10, the needle 106 that provides a puncture may beactuated axially (distal and proximal), i.e., may be caused to move,rather than being stationary as is described in most implementationsabove. FIG. 10 shows a side sectional view of such an implementation, inwhich the needle six is situated at the end of an elongated member 104which moves within a needle sheath 116. At a distal end of the needlesheath 116 is an element 112 which may be employed to assist deploymentof the funnel 114, having a proximal end 122 and a distal end 118. Anintroducer sheath 102 supports the funnel 114. Suction is provided alonga lumen 108.

FIGS. 11A-11C depict the distal end of the device and its interactionwith the septal wall 110 during use. FIG. 11A shows the initialengagement of the funnel 114 with the wall. Slight forward pressureagainst the wall, or application of initial vacuum, may result inpartial collapse or prolapse of the funnel which eventually brings theneedle sheath lumen in contact with the wall, as shown in FIG. 11B.Alternatively, the needle sheath 102 may be manually actuated to thispoint of contact. In either case, two separate seals are formed againstthe wall, and suction may then be isolated to the region between. Whenthe needle 104 with tip 106 is advanced, it may puncture the wall andaccess the adjacent space without compromising the suction, as shown inFIG. 11C and further explained below.

The actuation or movement may be employed by use of a knob on the handleforming the proximal end of the catheter. The same may be a short needlecoupled to the distal end of the device, and may be, e.g., connected toa reinforced polymeric lumen to transmit forces such as the push andpull needed for puncture. The needle may be actuated within the needlesheath, and the needle sheath may also isolate the suction to outsidethe needle and the sheath. In this way, once penetration has been madethrough the tissue, the negative pressure is maintained, rather thanbeing relieved by an in-rush of fluid such as blood into the body of thecatheter, and in particular, into the lumen from which negative or lowpressure was pulled. In some implementations, the needle sheath may bealso be allowed to actuate axially (distal and proximal) within thefunnel shaft. In other implementations, the needle sheath may be fixedto one position, to simplify procedural use of the device. In eithercase, the needle sheath serves house the needle and to isolate suctionto the space between its outer surface and the inner surface of thefunnel and funnel shaft.

FIG. 12 below depicts the key areas of the septal wall that are affectedduring the use of the device and this isolation of suction or negativepressure. The distal edge of the funnel initially contacts and makes aseal with the septal wall in the area indicated 118. The distal edge ofthe needle sheath contacts and makes a seal with the wall in the areaindicated 122. When negative pressure is applied to the device, thisnegative pressure is localized to the volume between elements 118 and122, which is outside of, and isolated from, the area of needle puncture(inside of element 122). In this way, the negative pressure in thevolume between elements 118 and 122, and the position of the deviceagainst the septal wall, is maintained during needle advancement,puncture, and penetration into the adjacent cavity (ie: the left atriumin a transseptal access procedure).

The needle sheath may also have a soft polymeric tip (ie: low durometerPEBAX or silicone) to enhance the seal against the septal wall. Inimplementations where the needle sheath is allowed to actuate within thefunnel shaft, the tip of the needle sheath may also be used subsequentto the needle puncture, to dilate the hole in the tissue formed by theneedle. In the implementation shown in FIG. 10 above, the tip of theneedle sheath is shown as a large tapered tip to enhance this dilation.

A proximal handle may be employed which incorporates a syringe likedevice to form a low pressure along the distal segment or within thecone of the device. The handle also allows user control over theextension of the needle, e.g., how far the needle is allowed to move oractuate. Movement increments may be provided by an appropriatemechanism, as well as stops and locks to control over extension.

In a related implementation, and referring to FIGS. 13A-13F, where thedevice is delivered through an introducer sheath or guiding catheter,the combination may be configured such that a slight pullback in thesheath deploys the funnel or cone. As may be seen, the septal wall 110,and in particular the fossa ovalis, may be punctured and penetrated invarious steps as shown, including deployment of the funnel 114 allowingsuction and puncture by the needle 104. The funnel or cone is preformedbut during delivery is constrained to be within the delivery sheath.Once outside the sheath, the funnel or cone adopts its preformed shapefor affixation to tissue. Forward pressure of the funnel creates theseal against the tissue. A vacuum or other low pressure (or negativerelative pressure) may then be applied, and the tissue may be eitherpulled across the needle or the needle gently extended through thetissue, or a combination. In either case, over extension of the needleand deleterious consequences to nearby tissues is avoided. It is notedthat even if the suction cup is not directly touching the tissue, oncesuction is applied, tissue still gets pulled into the cup, allowingsufficient contact for negative pressure to be drawn and maintained.

The benefits of implementations that provide isolated suction includethe maintenance of suction, equivalent to maintenance of position,before, during, and after puncture. Users are also offered additionalcontrol over the depth of needle puncture and/or access. The needle maybe hidden or withdrawn (or removed completely during delivery),mitigating risk to the funnel from damage due to the needle tip, andmitigating a stiff needle's affect on system flexibility.

Referring to FIGS. 14A-14D, having features 175 in the inner diameter ofthe sheath may cause an improved ability to fold the funnel 124 into thesheath. For example, referring to the figure below, improved folding maybe caused by having periodic features such as invaginations in theinterior of the distal end of the sheath.

In FIGS. 14A-14D, a sinusoidal or periodic invagination with fourfeatures. But, referring to FIG. 15, even a single discontinuity 126 inthe inner diameter 225 of the sheath can lead to enhanced folding. Thisdiscontinuity may be implemented by a single rib or spline, which asnoted creates a buckle point or collapse point for the funnel. A benefitof such implementations is that the same allows for a full conical shapefor the funnel, for optimum suction during use.

In another implementation, as shown in FIGS. 16A-16B, a funnel 250 maybe made inflatable, i.e., may be made out of a balloon, e.g., one thatis folded back on itself In the figure, the funnel is thus made of aballoon that has formed three segments 128 a , 128 b , and 128 c . Bycausing the funnel to take its deployed shape via inflation, the funnelmay be made very stiff during suction but very collapsible duringdelivery and retraction. As an example, an inverted 4.0 urethane balloonwas tested with good results. Suction was successfully obtained andmaintained.

In another implementation, shown in FIG. 17, a device 275 may include afunnel 132 in which the funnel is reinforced with, e.g., a nitinol coil134.

The nitinol coil reinforcing member provides additional radial strengthto the funnel, and can be retracted into the catheter prior to thecollapse of the funnel, allowing the funnel to easily collapse to asmall profile. The nitinol wire component may be attached to the needlesheath and advanced forward prior to creation of the vacuum to supportthe cone from collapse during application of said vacuum or delivered ina straight configuration, constrained by a straight delivery lumen, butupon deployment of the funnel, may be delivered into a coiled polymerictube that is molded as part of the funnel, allowing the coil to adoptits preformed shape. The nitinol wire may be pre-shaped as a coil, e.g.,as noted in the figure, and may adopt that configuration upon releasefrom the straight lumen in the delivery sheath or catheter. In this way,the funnel's suction stiffness is decoupled from its collapse stiffness.

As illustrated in FIGS. 18 and 19, a device 300 may include a funnel orcone 136 which may be implemented with a polygonal outer and/or innershape. Such may in some implementations create a variable thicknessaround the circumference of said cone, and may advantageously create“automatic” or inherent loci for collapsing, e.g., “collapse points”.Significant collapsability has also been discovered with funnels havingjust a single rib or spline on their surface, as the same createsanisotropy in folding, and thus induces a crease or other fold tohappen. Different size ribs 138 and 142 may be provided to furthercreate anisotropy for folding.

In an alternative implementation, the outer surface of the funnel orcone may have a particular shape, e.g., be heptagonal (or other shape),while the inner surface of the funnel or cone may have a differentpolygonal shape, which may be of lesser order than the outer surface,e.g., pentagonal, etc. Such adds flexibility to the funnel and providesinternal features to add support to the same, e.g., in a similar manneras ribs. Additionally, the heptagonal shape can spiral down the lengthof the funnel.

FIGS. 20-30B illustrate various other varieties of finals, including aribbed funnel 144 with a circular opening (FIGS. 20 and 21), aheptagonal funnel 146 (FIGS. 22 and 23), and a spiraling heptagonalfunnel 146′ (FIG. 24).

A variety of other funnel types may be employed to improve the collapsedprofile, apposition and sealing to various tissue surfaces, and/or theradial strength when deployed, and certain of these are illustrated inthe figures. These include a segmented funnel 148 (FIG. 25), a ribbedfunnel 152 (FIG. 26), a straight funnel 154 (FIG. 27), a straight ribbedfunnel 156 with a fluted distal end (FIG. 28), and a funnel 158 having anonuniform thickness (FIG. 29).

Variations of the systems and methods may include one or more of thefollowing.

In one variation, the cone or funnel portion of the device may be, inlieu of a solid cone, constituted of overlapping pleats, like flowerpetals. The petals may overlap so that the application of the vacuum ornegative pressure causes the same to appropriately seal to the tissue toallow the tissue to be pulled towards the needle. The pleats may beformed before or after a molding procedure of the funnel. The pleats maybe connected, such as in articles of clothing, or made be disconnected,such as like flower petals. In any case, the pleats allow convenientfolding and unfolding, e.g., retraction and deployment, of the funnel.

The funnel may be configured to be self-expanding or may be caused toexpand such as, e.g., by the nitinol wire described above. The entiretyof the interior of the funnel may be caused to be a low or negativepressure volume, or as noted above a central lumen (through which theneedle or other penetrating element is delivered) may define a volumewhich is not subject to low pressure.

The funnel may be injection molded, such as a molded PEBAX funnel, whichthen allows melt-flow bonding to the shaft of the catheter. The funnelmay employ a variable wall thickness, which allows the stiffness totransition from the portion of the funnel attached to the deliverydevice to the portion at a distal end. In the same way, the funnel shapeitself may transition from a proximal end to a distal end, as shown inthe figure below, to assist the ability of the funnel to properly seatand seal against tissue, e.g., by making the distal end more flexible.

The funnel may be made radio opaque, e.g., with embedded wires, e.g.,platinum or the like. Alternatively, instead of embedded wires, thefunnel may be heat bonded with radio opaque polymer tubes. In yetanother implementation, the cup material itself may be compounded withradio opaque materials such as tungsten, barium, or the like. The radioopaque features may have specific geometries to assist the physician invisualization of the orientation of the system under fluoroscopy.

The funnel may be made flexible or articulating, the neck of the funnelor cone may also include bellows or have a bellows-like design similarto a strain relief to enable the neck of the funnel or cone to haveincreased flexibility so as to be able to create a strong enough seal toallow the funnel to hold against a surface that is not perpendicular tothe axis of the catheter.

As in the polygonal funnel structures described above, the funnel mayinclude one or more elements to impart a forced or assisted folding ofthe funnel or cone during retraction of the funnel into the deliverysystem. The funnel may be formed to have a “memory”, such that duringretraction and extraction, the same transforms from a collapsed to adeployed configuration (and vice versa) in a consistent manner.

The funnel may further be provided with a plurality of electrodes alongits distal end, e.g., the edge of the funnel that contacts the tissue,which may then be employed to enable mapping to be used to identify theFO for proper location to make a puncture.

The funnel may also be provided with a series of needles positionedalong the edge or rim, e.g., the distal end, to enable longer-termfixation of the funnel to the tissue. The needles may also be employedto hold the device for procedures such as a closing of the incision madeby the main or central tissue-penetrating element, e.g., for proceduressuch as open-heart procedures for valve repair or replacement. In thisapplication, once access to the heart is made to the chest, a deviceaccording to the present principles may be advanced to the exteriorsurface of the heart. Low pressure may be applied as discussed to sealthe device to the heart. The exterior needles arranged around thecircumference of the funnel may then pierce the heart in addition to thevacuum to hold the position for longer procedures. The needles mayfurther be provided with a suture mechanism to suture the device to thetissue. At the end of the procedure, the ends of the suture may bepulled and the access point closed.

The vacuum may be caused by a syringe attached to the handle orincorporated within the handle which is in pressure communication withthe lumen at a proximal end of the catheter, the lumen being in pressurecommunication with an interior of the funnel at a distal end. Pullingback on a plunger of the syringe changes the shape of the tissue via thepressure communication, and the change of shape may be convex orconcave, depending on the shape of the funnel, such that the tissue isbiased towards the tissue-penetrating element such as the needle. Alocking syringe (i.e.: Merit Medical VacLok Syringe) may be useful tomaintain the negative pressure for extended periods of time during theprocedure. In some implementations, the pressure may be drawn locally,at the distal end of the catheter, rather than remotely by a device suchas a user-operated syringe. This element and procedure may also increasetissue/blood perfusion locally that might also benefit the patientdepending on clinical use.

The catheter may include more than one lumen, although generally atleast one is required for the pressure communication. Other lumens maybe employed for the transmission of gases or fluids or a guide wire orother devices such as biopsy needles etc. In the implementation notedabove, where the funnel is inflatable, a lumen may be employed todeliver an inflation fluid or gas.

The needle sheath lumen may be spring loaded or adjustable in length toprovide optimum opposition to the tissue being penetrated by the needle.Additionally, this lumen can provide a channel for blood to flow fromthe opposite side of the tisse after the needle has penetrated. Thiscould be used as an indicator that the needle has penetrated or forpressure readings or blood coagulation or viscocity measurements to aidthe physician in obtaining and or monitoring in-procedure hemodynamicconditions commonly known as Activated Clotting Time (ACT) measurements.

The tissue-penetrating element may be solid or may have an internallumen so as to enable passage of a guide wire. The same may also be alead, biopsy tools such as forceps, or the like. A lumen within theneedle or other tissue-penetrating element may be appropriately-sized toallow some of the septal or other tissue to be pulled into the lumen,e.g., for additional fixation, drug delivery, a procedure, a biopsy, orthe like. The needle or other tools delivered thru said lumen of thisdevice may also transmit an energy source as a therapeutic agent thatinclude but not limited to RF energy to cauterize, ablate or performother therapeutic elements.

Systems and methods according to present principles may be applied inother areas of the body i.e. lungs, heart, and external of the heart aswell. For example, within the heart, systems and methods may be employedto aid in lead placement for pacemakers. For example, with a funnelappropriately miniaturized, TS access may be achieved and theminiaturized device delivered through the TS sheath to enable a lead tobe placed in the atria or ventricles or other organs. The funnel or conemay be advanced to the area of interest in the atria or ventricles andthe syringe or other device used to cause a low-pressure volume to becreated, affixing the funnel to the tissue site. By using a differentlumen, e.g., a working lumen, a lead can be advanced and may penetratethe tissue or by using the lumen of the needle of the device, e.g., bypassing the lead through the lumen of the tissue-penetrating element,and into the tissue for ICD procedures. Other lumens may also beemployed. A reverse procedure may be employed for lead extraction.

Exterior of the heart, systems and methods according to presentprinciples may be employed in a number of indications, including inendoscopy, gynecology, laparoscopy, other surgical procedures, andgenerally any procedure involving passage through a tissue. Systems andmethods according to present principles may be employed to directlyaccess tissue or organs for minimally-invasive procedures without theneed to use the body's vascular system. The systems and methodsaccording to present principles may be employed to hold tissue by themaintenance of the suction, yet subsequently have a separate lumenemployed to enable physicians to directly access the tissue or adjacenttissues, e.g., organs, for biopsy, ablation, etc.

Following TS access, a guide wire may be advanced and the sheath, e.g.,an SL1 (8F sheath) may be exchanged for a 12 to 14 French sheath orother device.

Instead of the needle, a tip ablation electrode may be advanced toprovide and perform ablation while the suction cup holds the position.The suction cup can also draw cooled saline over the tip to cool theelectrode, and moreover the suction cup may prevent emboli from floatingin the left atrium, improving the safety profile for ablation. In otherimplementations, other cone shapes besides a round: shape may also beemployed. For example, the outer geometric shape may have a number ofsides while the inner shape may have one or more less sides to formvariations of cone thickness along the length of the cone to improveresistance to compression under vacuum and allow the points of the coneto provide “rib” like features for stability and controlled collapse ofthe cone during introduction and withdrawal from the sheath or guidecatheter.

FIGS. 30A and 30B indicate in oblique and end views an example 525 ofsuch a cone shape 162.

In yet another implementation, shown in FIGS. 31-39, termed a “bullettip” implementation, a device 550 according to present principlesincludes a bullet tip shape 166 which is used to enhance expansionand/or deployment of the funnel/cone 164, or suction cup. Thisimplementation may also take advantage of an introducer tool, and mayalso employ various slitting mechanisms as alternatives to dilation. Theslitting mechanisms may use a reverse cutting technique or tool.Moreover, an inverted funnel may be employed in conjunction with thebullet tip.

In particular, and referring to the figure below, a device according topresent principles 575 may include a needle sheath component 102′ havingin one portion a shape of a bullet tip 166 (also just termed a bullettip) may be employed at the distal tip of the sheath 102′ and within thefunnel 164. The bullet shape, in particular at its proximal end, servesin part to initiate funnel expansion in a conical shape due to itsflared nature.

The bullet tip has a shape similar to that of a traditional dilator,especially when retracted to abut the remainder of the sheath, asdescribed below. Various views are shown in the figures.

As seen in FIG. 34A, the bullet tip with relief cuts may further havefluid transmission features 576, such as slits, channels, conical shapedslots , or gaps that run from a distal end to a proximal end, and thatprovide fluid transmission, allowing the improved fluid flow forsuction, vacuum, or negative pressure. The conical shaped and slots alsoallow the suction to be increased by creating additional vorticies. Theconical shaped slots may include a single or multiple slots that performseveral functions in addition to multiplying the force of vacuum, fluidpath, etc..

Other features may include that the bullet tip is radio opaque, so as toallow visualization of the distal tip of the device under fluoroscopy.In another implementation, the tip may have a metallic band encircling apolymer tip, e.g., made from Pt/Ir, etc. The bullet tip may further beformed from a radioopaque compounded polymer.

Following transseptal access via a wire, the bullet tip may assist indilation, providing a smooth OD transition to the TS sheath, and in thisway allows the replacement of the traditional sheath dilator.

As noted above, and referring to FIG. 35, the bullet shape providesinternal support to the funnel, especially during suction. It props thefunnel open, as shown by the force arrow 173, prevents collapse of thefunnel under vacuum, and improves the suction force (see arrow 164). Itfurther has the advantage of allowing thinner funnel walls and ashallower taper angle, providing an important advantage not seen inprior systems.

In an enhanced implementation, and referring to FIGS. 36-37, a device166′ includes a referring to FIG. 40 blade 178 disposed on the proximalside of the needle sheath bullet. In this way, the bullet tip isadvanced past the fossa ovalis, then the gblades slit the FO uponretraction of the needle sheath back through the FO. While two bladesare shown, it will be understood than any number of blades may beemployed, including just one.

Referring to FIGS. 38-39, a device 166″ according to present principlesmay incorporate another exemplary slitting mechanism in the form ofsharpened wires 182 bonded to the needle sheath (not necessarily on thebullet itself). The blades are constrained inside the funnel sheathuntil the bullet is advanced into the left atrium. Upon advancement, theblades are released into the left atrium. Upon retraction of the needlesheath back through the FO, the blades slit the FO as desired. As asafety feature, only the back side of the wire is sharpened. The bladeis thus only exposed when needed to cut the FO. Upon retraction backinto the funnel and/or funnel lumen, the blade edges are shielded untilthe same are safely in the device. In FIG. 39, a device 166″' is shownwith just one blade 184 attached.

FIGS. 40A-40J illustrate an exemplary method of use. Referring to FIG.40A, a device 650 includes an introducer sheath 205 having a collapsedfunnel within the sheath. An introducer tool 204 may be employed toassist introduction of the device into a transseptal sheath 202. In FIG.40B, the device having a tip 208 is pushed against the septal wall 206.The funnel 210 deploys in FIG. 40C, e.g., via pullback of the sheat, andsuction is activated in FIG. 40D. After suction is applied, the needlemoves easily through the FO, or in some cases the suction itself isenough to cause the FO to move past the needle, providing the desiredpuncture.

Needle 212 access is shown in FIG. 40E, followed by guidewire 214deployment in FIG. 40F. The needle is retracted in FIG. 40G, and suctionis stopped and the funnel retracted/collapsed in FIG. 40H. Pushing thesheath forward may recapture the funnel/cone. Dilation may be performed(FIG. 401), i.e., moving the sheath forward with the bullet tip mayprovide a dilation function, and the device may then be removed as inFIG. 40J, in some cases leaving the TS sheath in place, along with theguidewire if desired.

Advantages of implementations according to present principles mayinclude one or more of the following. Systems and methods allow evenphysicians to single-handedly effectively manipulate the catheter toallow TS access. The system is fast and easy to deliver. For TS access,it is expected to take less than 20 min to obtain left atrial access formost physicians.

1. A method of gaining access through a septum, comprising: delivering aguidewire to a selected location proximal to a septum; delivering atransseptal assembly over the guidewire, the transseptal assemblyincluding a steerable sheath having an elongated member with a proximalend, a distal end, and an inflatable funnel coupled to and surroundingthe elongated member at the distal end, the inflatable funnelsubstantially collapsed against the elongated member in a retractedconfiguration, the inflatable funnel further having an inflatedconfiguration having a proximal end with a first radius and a distal endwith a second radius, the second radius greater than the first radius;inflating the inflatable funnel; placing the inflated funnel against theseptum and providing forward pressure against the septum; moving apiercing element in a distal direction through the elongated member andagainst the septum, the piercing element including an activatable radiofrequency element; and activating the radio frequency element topuncture the septum, such that the inflatable funnel provides a stablebase for a transseptal puncture to occur, and is stiff when inflated butcollapsible during delivery and retraction.
 2. The method of claim 1,further comprising activating a governor configured to move the piercingelement against the septum and to inhibit movement of the piercingelement past a pre-specified point.
 3. The method of claim 1, furthercomprising steering at least the distal end of the elongated memberusing a steering mechanism at or adjacent to a handle of the transseptalassembly.
 4. The method of claim 1, further comprising causing movementof the piercing element against the septum while controllingover-extension of the piercing element.
 5. The method of claim 1,further comprising activating an ultrasound element to visualizetransseptal access locations.
 6. An assembly for transseptal access,comprising: a steerable sheath including an elongated member having aproximal end and a distal end; an inflatable funnel coupled to andsurrounding the elongated member at the distal end, the inflatablefunnel substantially collapsed against the elongated member in aretracted configuration, the inflatable funnel further having aninflated configuration having a proximal end with a first radius and adistal end with a second radius, the second radius greater than thefirst radius, the inflated configuration caused by inflation through aninflation lumen; such that the elongated member and the inflatablefunnel are configured to be delivered to a septal location, and suchthat upon inflation the funnel is configured to transition from theretracted configuration to the inflated configuration; and a piercingelement movable in distal and proximal directions through the elongatedmember, the piercing element configured to pierce the septum when thefunnel is in the inflated configuration and when the funnel iscontacting the septum, the piercing element including an activatableradio frequency element, such that the inflatable funnel provides astable base for a transseptal puncture to occur, and is stiff wheninflated but collapsible during delivery and retraction.
 7. The assemblyof claim 6, wherein the first radius is between about 3 French to 10French and the second radius is between about 2.5 mm and 15 mm.
 8. Theassembly of claim 7, wherein the first radius is between about 5 Frenchto 8 French and the second radius is between about 5 mm and 10 mm. 9.The assembly of claim 6, wherein the elongated member or the funnel orthe piercing element further comprises a radioopaque element.
 10. Theassembly of claim 6, wherein the assembly further comprises a dilator.11. The assembly of claim 6, wherein the elongated member has furtherdefined a guidewire lumen therein, the guidewire lumen extending fromthe proximal end to the distal end.
 12. The assembly of claim 6, whereinthe piercing element is on a distal end of a dilator, is hollow, or isdisposed off-axis relative to an axis of the elongated member.
 13. Theassembly of claim 6, further comprising a governor configured to movethe piercing element against the septum and to inhibit movement of thepiercing element past a pre-specified point.
 14. The assembly of claim6, wherein the inflatable funnel is comprised of a soft durometerpolymer.
 15. The assembly of claim 14, wherein the polymer of theinflatable funnel has a memory or an inherent geometric shape, to helpthe inflatable funnel deploy into the inflated configuration uponinflation.
 16. The assembly of claim 14, wherein the inflatable funnelis formed by folding the polymer back on itself.
 17. The assembly ofclaim 6, further comprising a steering mechanism at or adjacent to ahandle of the transseptal assembly, the steering mechanism configured toallow at least the distal end of the elongated member to be steered. 18.The assembly of claim 6, further comprising an ultrasound element tovisualize transseptal access locations prior to puncture.
 19. Theassembly of claim 6, wherein the piercing element is coupled to areinforced polymer to transmit forces such as a push and pull needed forpuncture.
 20. The assembly of claim 6, wherein the distal end of thetransseptal assembly includes a metallic band encircling a polymer tip,or includes a radioopaque compounded polymer.
 21. The assembly of claim6, further comprising a lock configured to allow movement of thepiercing element against the septum while controlling over-extension ofthe piercing element.
 22. A method of gaining access through a septum,comprising: delivering a guidewire to a selected location proximal to aseptum; delivering a transseptal assembly to a selected location bysteering the same using a steering mechanism controlled at or adjacent ahandle, the transseptal assembly having proximal and distal ends and afunnel coupled to and substantially surrounding the elongated member atthe distal end, the funnel substantially collapsed against the elongatedmember in a retracted configuration, the funnel further having anexpanded configuration upon inflation with gas through an inflationlumen, the expanded configuration having a proximal end with a firstradius and a distal end with a second radius, the second radius greaterthan the first radius, such that the funnel is stiff when inflated butcollapsible during delivery and retraction; inflating the funnel;placing the funnel against the septum and providing forward pressureagainst the septum to provide a stable base for a transseptal punctureto occur; moving a piercing element in a distal direction through theelongated member and against the septum, the piercing element includingan activatable radio frequency element; and activating the radiofrequency element to puncture the septum.
 23. The method of claim 22,further comprising activating a governor configured to move the piercingelement against the septum and to inhibit movement of the piercingelement past a pre-specified point.
 24. The method of claim 22, whereinthe delivering and steering further comprises visualizing a portion ofthe transseptal assembly under fluoroscopy, the portion having aradioopaque marker.
 25. An assembly for transseptal access, comprising:a steerable sheath including an elongated member having a proximal endand a distal end; and an inflatable funnel coupled to and substantiallysurrounding the elongated member at the distal end, the inflatablefunnel substantially collapsed against the elongated member in aretracted configuration, the inflatable funnel further having anexpanded configuration when inflated through an inflation lumen, theexpanded configuration having a proximal end with a first radius and adistal end with a second radius, the second radius greater than thefirst radius; and a piercing element including an activatable radiofrequency element disposed on a dilator movable in distal and proximaldirections through the elongated member, the radio frequency elementconfigured to puncture transseptal tissue when activated, such that theinflatable funnel provides a stable base for a transseptal puncture tooccur, and is stiff when inflated but collapsible during delivery andretraction.
 26. The assembly of claim 25, wherein the elongated memberor the funnel or the piercing element further comprises a radioopaqueelement.
 27. The assembly of claim 25, wherein the piercing element ishollow or is disposed off-axis relative to an axis of the dilator. 28.The assembly of claim 25, further comprising a governor configured tomove the piercing element against the septum and to inhibit movement ofthe piercing element past a pre-specified point.
 29. The assembly ofclaim 25, wherein the inflatable funnel is comprised of soft durometerpolymer, and wherein the inflatable funnel is formed by folding thepolymer back on itself.
 30. The assembly of claim 25, further comprisinga steering mechanism at or adjacent to a handle of the transseptalassembly, the steering mechanism configured to allow at least the distalend of the elongated member to be steered.